I haven't checked but the mk2 looks like do not have hw (i can hear the guide moving when I tilt the mk2). I remove the hw from my X for pellets, was giving too much tention.
The hw is really not necessary for less than 145b probably (or so), the head gives too much pre tention to the spring, on lower bar settings, avoiding have less tention even when you unscrew the hts all the way. Waisting air. It happen to me before on testing.
The 30gn gave me good results on the pellet liner @ higher reg pressures and the 22.5 vk too @ 1000 fps